The present invention relates to a refrigerating air conditioning apparatus and more particulary to an improvement in a liquid separator therefor to be provided in the pipeline connecting the compressor and the evaporator therein.
Hitherto, there has been used as a liquid separator for a refrigerating air conditioning apparatus of this kind a separator as shown in FIG. 1 of the attached drawings, wherein the reference numeral 1 designates a container, 2 an inlet pipe for a refrigerant gas from an evaporator (not shown), 3 an exit pipe for the refrigerant gas, 4 a liquified refrigerant coil provided at the bottom part of container 1, 10 a suction pipe leading to a compressor (not shown), and 11 a temperature sensing tube mounted on suction pipe 10 and adapted to coact with a flow rate regulating valve (not shown) to regulate the flow of the liquified refrigerant to the evaporator.
The operation of the liquid separator shown in FIG. 1 is as follows.
The refrigerant gas leaving the evaporator (not shown) enters container 1 through refrigerant gas inlet pipe 2 with a small quantity of the liquified refrigerant being entrained therein. In container 1 the velocity of the refrigerant gas is rapidly retarded so that the liquid portion contained in the refrigerant gas drops in container 1 due to the difference in specific weight between the liquified refrigerant and the refrigerant gas, only the gas portion being sucked to the compressor (not shown) from refrigerant gas exit pipe 3 through suction pipe 10. The liquified refrigerant thus separated from the refrigerant gas and accumulated in the bottom of container 1 cools the high pressure liquified refrigerant which is flowing within liquified refrigerant coil 4, is in turn gasified, and is also sucked into the compressor through exit pipe 3. The high pressure liquified refrigerant flowing within liquified refrigerant coil 4 is supplied to the evaporator to be evaporated therein, returning to container 1 through gas inlet pipe 2. In this case, it is desirable that at least a portion of the liquified refrigerant supplied to the evaporator be allowed to be maintained in the liquid state until it reaches the exit of the evaporator in order to increase the capacity of the evaporator by utilizing the latent heat of the liquid portion of the refrigerant therein. However, since there is the fear of possible damage to the compressor if it happens to suck in the liquid portion of the refrigerant, it is the usual practice that the liquid portion is separated from the refrigerant gas by a liquid separator, and in addition suction pipe 10 of the compressor is provided with temperature sensing tube 11, a control sensor for a flow rate regulating valve (not shown) for the high pressure liquified refrigerant to be supplied to the evaporator, to sense the temperature of suction pipe 10 so that the liquid portion is not carried to the compressor.
However, since the conventional liquid separator has the construction described above, it takes a long time before the liquid separator is cooled and also before the temperature sensing tube is cooled at the time of starting the air conditioning apparatus after it has been at a standstill for a long time, and on the other hand an excessive amount of the liquified refrigerant accumulates in the container at the time when the temperature sensing tube is about to be cooled. Thus, it will be appreciated that the conventional liquid separator as exemplified herein inevitably exhibits a tendency to be subjected to a time lag before it is properly operated. Therefore, owing to this time lag, when the apparatus restarts, as the flow rate regulating valve begins to throttle the flow of high pressure liquified refrigerant due to the sensing of a low temperature by the temperature sensing tube, the supply of refrigerant gas to the compressor becomes small, the suction pressure of the compressor being lowered temporarily to an extraordinary valve, and an abnormal stoppage of the compressor may occur. Such a phenomena constitutes one of the defects inherent in a conventional liquid separator in a refrigerating air conditioning apparatus.